+1 vote
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As we have resistance also with same meaning that is resist flow of current.How are they both different from each other ?
related to an answer for: Define Impedance
asked Nov 30, 2015 in Electro-Communication by transformer | 109 views

1 Answer

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One can say that The very nature of Impedance and Resistance is same.

Which resist the flow of current is known as Resistance. And is represented by R.

Now in AC circuits besides Resistance, it has Capacitance and Inductance. And this Capacitance, Resistance and Inductance together form Impedance which is denoted by Z.

One can say the Impedance for DC circuit is its Resistance

Edit : (copied from comment)

Well Impedance of any circuit (DC or AC) is comination of R,LC (Resistance, Inidcutance, Capacitance). We can say Total Impedance Z = ZR+ZL+ZC
Now  impedance of inductors increases as frequency increases
ZL = jwL
and, impedance of capacitors decreases as frequency increases
ZC=1/jwC
now both Zl and ZC is frequency dependent component.
So for AC circuit Z=ZR+ZL+ZC
and in DC cicrcuit, we don't have any frequency,
so it becomes Z=ZR
In DC circuit Resistance is the Impedance (due to no existance of capacitance and inductance)
answered Dec 6, 2015 by Arka
edited Dec 26, 2015 by slow_learner
so DC circuits dont have impedance ?
Well Impedance of any circuit (DC or AC) is comination of R,LC (Resistance, Inidcutance, Capacitance). We can say Total Impedance Z = ZR+ZL+ZC
Now  impedance of inductors increases as frequency increases
ZL = jwL
and, impedance of capacitors decreases as frequency increases
ZC=1/jwC
now both Zl and ZC is frequency dependent component.
So for AC circuit Z=ZR+ZL+ZC
and in DC cicrcuit, we don't have any frequency,
so it becomes Z=ZR
In DC circuit Resistance is the Impedance (due to no existance of capacitance and inductance)